Frame for divided water tank

ABSTRACT

A tank has a circumferential wall defined by a plurality of separate elements in the form of vertical staves. Adjacent elements are shaped so that they are squeezed together to prevent leakage past adjacent elements. Hoops surround the wall elements. One hoop is a plurality of segments. Truss rods connect separate elements of the hoop to a support inside the tank. The truss rods of the hoop connect the hoop segments to the inside support in the tank and are tightened thereto for drawing the hoop wall elements inward to the truss rod supports, squeezing the adjacent wall elements together for preventing leakage between adjacent elements. A divider across the tank has the supports thereon for receiving the ends of the truss rods in the tank. Other staves define a divider of staves. Vertical beams support them.

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation of U.S. patent application Ser. No. 14/673,156,filed Mar. 30, 2015, which is a continuation of U.S. patent applicationSer. No. 13/623,670, filed Sep. 20, 2012, now U.S. Pat. No. 9,027,773,issued May 12, 2015, which is based on and claims priority to U.S.Provisional Application Serial No. 61/660,461, filed on Jun. 15, 2012and entitled FRAME FOR DIVIDED WATER TANK, the disclosures of which areincorporated by reference herein.

BACKGROUND OF THE INVENTION

On a large number of commercial and industrial buildings, a large watertank is placed on the roof to supply water for standard uses andemergency uses, particularly if the regular water supply to the buildingis interrupted. The water tanks are typically either made of metal or ofwood. The invention hereof is primarily concerned with a wooden watertank, wherein the body of the tank is entirely of wood, although it maybe applicable to a wood tank that is all or in part clad with a metalcovering.

A typical water tank has an undivided water compartment that is notinternally divided into two or more compartments. If the interior of thetank is divided into two or more compartments or chambers, they arepreferably sealed from each other so as to provide that number ofseparate, and independently controllable water supplies from a singletank. Of those water tanks with separate compartments, it is only knownto use tanks made of metal and to separate the compartments by placingdividing walls within the metal tank. When the tank is of metal, thecompartments dividing wall is also of metal and the tank is assembled byattaching, e.g. by welding or other leak resistant connection, thedividing wall to the interior of the tank.

Applicant is unaware and prior art is not known which discloses a watertank, particularly of the type used on the roof of a building, which isa wooden tank that is internally divided into compartments andparticularly a wooden tank that is divided by a wooden dividing wall.

Wooden tanks have certain benefits, including preference by a customer,satisfying local building codes, local availability of materials,sealable against leakage during construction and extended seal due tothe effect of water on wood, minimal prolonged exposure of the water tometal due to wood surfaces and to attachment materials in the water,which may corrode unless made of more expensive corrosion resistantmetal and other reasons known to persons of skill in the art.

SUMMARY OF THE INVENTION

A separated compartment divided wooden tank according to this disclosureis a preferably circular shape shell defining the wooden tank, sincethat is the shape that can best withstand the forces of clampingtogether the wood staves of which the tank shell and the dividing wallare preferably constructed. The staves forming the tank are preferablynarrow width boards that extend over the full height of the tank.Neighboring staves have abutting edges in sealing contact over theentire height of the tank.

The compartment dividing wall (or walls) in the tank is also preferablycomprised of a plurality of narrow width (i.e., short height when thewall is assembled) boards or wood staves. Those boards or staves may bearrayed horizontally, one atop the other, and the abutting edges ofneighboring staves or boards are in sealing contact across the entirewidth of the dividing wall. The dividing wall is securely attached tothe interior of the wood tank wall.

All of the adjacent neighboring staves of the tank and adjacentneighboring boards or staves of the dividing wall and the connectionsbetween the dividing wall(s) in the tank and the wall (shell) of thetank and the floor of the tank are all securely attached, as describedbelow, to seal the tank, the dividing wall(s) and the connectionsbetween the dividing wall(s) and the tank and the tank bottom wall,thereby forming two or more essentially leak proof compartments in thesame tank. The compartments so formed are independent of each other sothat one may be used, filled, emptied, etc. without affecting theother(s). Although two compartments are described above and in thefollowing more detailed description, the tank may be divided by dividingwalls into more than two separate compartments, using dividing wallsformed of wood in the manner described above. The attachments betweentank parts preferably avoid the use of possibly toxic adhesives andconnecting elements between tank parts and eliminates or minimizes theuse of possible corrodible metal within the tank, including rods, beamsand fastenings exposed to water in the tank.

Several types of element fastenings and stave clamping devices are usedfor the tank. They may include some or all of the following. Severalhoops wrap around the outside of the tank at spaced apart heightintervals along the tank. The hoops may be drawn tight, squeezing theabutting edges of neighboring vertical staves together as the hoops biasthe staves together to seal neighboring staves against each other toprevent leakage through the tank wall.

Sets of axially oriented and axially extended beams are arrayed atspaced intervals over the cross direction, e.g., radial width along thedividing wall. Those beams are clamped against opposite sides of thewall, usually in opposing pairs. They clamp the individual horizontalboards of the dividing wall in vertical alignment.

Elongate first truss rods extend between nearly oppositely locatedstaves around the tank. The first truss rods are tightened to therespective staves to urge nearly opposite staves of the tank wall towardeach other, particularly in the vicinity of a connection between thedividing wall and the tank wall. The first truss rods or other types ofconnections draw the tank wall against the lateral end edges of thedividing wall and against the periphery of the tank bottom. The firsttruss rods also may pass through the axially extended beams. Connectionsfor the beams located at the top and the bottom of the dividing wallsqueeze the boards of the dividing wall together from top to bottom forthat wall, sealing that wall against leakage.

There may be second, generally radial truss rods extending from afixture on the dividing wall out to the wall of the tank at intervalsaround the circumference of the tank. These rods are also attached atthe tank wall and tightened to bias the staves of the wall radiallyinward.

All of the rod connections to and through the walls and the beams aretightened where appropriate and possible, using preferably non-corrodingmetal connections. Essentially all of the numerous adjacent parts aredrawn together by tightened rods for clamping parts to prevent leakagebetween adjacent connected parts.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic perspective view of a first embodiment of acompartmented wooden water tank. Some elements are partially removed topermit viewing.

FIG. 2 is a perspective view of a top section of the tank in FIG. 1;

FIG. 3 is a view from above into the top section of the tank in FIG. 2;

FIG. 4 is a perspective view of a middle section of the tank in FIG. 1;

FIG. 5 is a view from above at a cross section at the middle section ofthe tank in FIG. 1;

FIG. 6 is a perspective view from above at a cross section at the bottomsection of the tank in FIG. 1;

FIG. 7 is a view from above at a cross section at the bottom section ofthe tank in FIG. 1; and

FIG. 8 is an elevational, cross-sectional view of the tank in FIG. 1.

DESCRIPTION OF PREFERRED EMBODIMENTS

Alternative embodiments of wooden tanks with a dividing wall may beenvisioned by one skilled in the art.

In a first embodiment of FIGS. 1, 8, a tank 10 includes a cylindricalshell 11 comprised of wood staves and includes a flat wood tank bottomor floor 12 to which a sidewall 11, 14 of the tank is attached. There iswood dunnage 34 below the floor 12 which supports and stiffens the flooragainst the weight of water above the floor. The open top of the tank isclosed by a tank top 16 also preferably of wood. The top 16 of the tankis also leakage resistant, but the water level does not pass over thetop of the tank and there is little danger of leakage in or out. Thereis no pressure head from water above the top of the tank, although thatpressure head is present based on water above the tank bottom. Inaccordance with the preferred embodiments of the invention, the bottom12 of the tank and the sidewall 14 of the tank are wood constructions,without metal as one of the elements of those tanks, except forfastening and clamping devices, described below.

The tank 10 is typically about 12 to 18 feet in height and about 12 to18 feet in diameter as the designer of a specific tank designates. Thesedimensions are a matter of choice and are dependent in part upon thesize and configuration of the building for which the tank is providedthe desired size and water storage capacity, and the duration of a waterstorage in the tank.

The horizontal cross-section of the tank shell 11 is circular, as thatis a preferred shape for supporting the tank against radial directioncollapse when pressure is applied to the tank by hoops 18 that stiffenand tension the tank wall 14 to maintain the shape of the tank withoutcollapse.

The tank shell wall is comprised of many individual narrow width woodenstaves or boards 20, 22, 24, et al. of the height or the length of thetank. Lateral edges of adjacent staves are held next to one another todefine the circular cylinder sidewall 14 of the tank.

A plurality of hoops 18, 19 each extending completely around the outsideof the tank wall 14, are arrayed at selected axially spaced heightintervals of, for example, about one foot apart. That spacing is amatter of choice. In this embodiment, the top and bottom hoops 18 of thetank are unbroken around the entire circumference. The threeintermediate hoops 19 are comprised of circumferentially separatedarcuate segments 21, each of L-shaped cross section. Each segment iswrapped over a respective group of adjacent staves. The segments aredrawn radially inward by later described second radial truss rods. Thehoops are typically of metal. The hoops are strong enough to retain thebelow described dividing wall 40 between tank compartments sealed to theshell of the tank, when the compartments are filled or empty. Theunbroken hoops 18 are tightened around the wall 14 by standardtightening devices 23 for a hoop, which may include opposing separatedtabs joined by a connection element.

The wall 14 and its staves 20, 22, 24, et al. are arranged around thefloor 12 of the tank, which thereby defines the diameter andcircumference of the tank wall. A leakage preventing groove 28 passingaround the bottom of the tank wall through each of the staves 20, 22, 24is of a vertical cross-section like the peripheral edge 32 of the tankfloor 12, and that edge projects into and is received by the groove 28at the bottom of the wall. The edge 32 fitted into the groove 28provides a liquid leakage preventing fit. Additional leakage resistantelements, such a plastic gasket placed in the base of the groove 28 mayhelp prevent leakage.

A wooden dividing wall 40 in the tank extends the height of the tank andacross the full width of the tank preferably along a diameter of thecylindrical tank. This defines two water containment compartments 37, 39at opposite sides of the wall 40. But, the wall could be at a chord offa diameter, resulting in two compartments that are separated by the wallbeing of different volumes.

The dividing wall 40 is preferably comprised of a stack of boards orstaves 41, 42, et al. for example, of the type of which the wall 14 ofthe tank is fabricated, although the latter is not required. Thedividing wall 40 may be comprised of boards or staves of different width(vertical height) and thickness than the staves 20, 22, 24 forming tankwall 14. It has thus far been found preferable to have at least most orall of the individual boards 41, 42 of the dividing wall be short inaxial direction height and extend over the entire diameter or chord ofthe tank, defining a vertical stack of the short height, long widthboards. However, the dividing wall might instead be arranged with aplurality of adjacent staves extending in a vertical direction, like theouter shell wall 14.

The dividing wall 40 should be securely attached to the sidewall 14 ofthe tank and to the floor 12 of the tank so that the dividing wall doesnot permit leakage across that wall between the compartments 37 and 39,no matter how each of the compartments might be differently filled.

The bottom edge 44 of the dividing wall 40 is received in acorrespondingly shaped groove 46 in the floor 12 of the tank. The edge44 and the groove 46 are respectively so sized and shaped as to sealagainst leakage of water past the bottom edge of the wall. An additionalleakage prevention device may be supplied at the groove, such as a stripof flexible plastic, or gasket or washer material, or the like. Thatsame type of connection is not required for the top of the tank, becausethere is no pressure head of water above the tank that is urged to passaround the wall.

Each lateral edge 49 of the dividing wall 40 is received in acorrespondingly shaped groove 51 in diametrically opposite staves 53 and54 of the tank wall 14. The edge 49 of the dividing wall and the groove51 in the tank wall are shaped and sized to prevent leakage of waterpast the dividing wall. An additional element to prevent leakage, suchas a strip of a plastic material et al., may be placed along the grooveto prevent leakage.

Especially when the dividing wall 40 is comprised of a plurality ofboards 41, 42 extending horizontally, there is a possibility that waterpressure on the wall, warping of the wood or some shifting of the boardsmight occur, so that the boards of the dividing wall might becomemisaligned above one another and present leakage paths for water pastthe wall. This is not likely to happen to the staves or boards of theouter wall 14 of the tank because the hoops 18, 19 hold those stavestightly and the staves held tightly by the hoops are not likely todeform or shift.

At spaced apart positions across the (diametric) width of the dividingwall 40, there are pairs of opposing I-shaped support beams 48 at oneside of the wall and 50 at the opposite side of the wall. Each of theI-beams extends the full height of the dividing wall 40. Each pair ofbeams is connected by a plurality of fasteners 52 between the I-beams.When the fasteners 52 are tightened, the beams are pressed against theopposite sides of the wall 40 and that fixes the boards 41, 42, et al.of the dividing wall in alignment over the height of the wall and keepsthe adjacent horizontal boards abutting to seal the dividing wall.

First truss rods 54, 56 are spaced from, but near to, respectiveopposite sides of the dividing wall 40. With the dividing wall on adiameter of the tank, each of the first truss rods 54, 56 extends on achord across the width of the tank. The first truss rods pass throughholes 57 formed in the I-beams 48, 50. The first truss rods pass throughthe side walls of the tank. The above described hoop segments 19 haveholes that receive the ends 59 of the first truss rods 54, 56, so thatthe first truss rods are tightened into the hoop segments 19 on theoutside of the shell of the tank. This pulls radially inward the stavesof the tank wall including the staves that receive the first truss rods54 and 56. This tightens the hoop segments 19 against the staves. Thereis a respective channel cover 58 at the top of the tank just outward ofthe truss rods 54 and 56.

In FIGS. 4 and 5, there is a fixture 60 and 62 at each side of thedividing wall 40 just below the height of a respective first truss rod54 or 56. The fixtures 60, 62 are at approximately the radial center ofthe dividing wall along the diameter of the tank wall 11.

At each of the fixture 60, 62, there is a respective plurality ofsecond, radial truss rods 64 at one fixture 60 and 66 at the otherfixture 62. Because the fixtures 60, 62 are outward of the dividingwall, the second truss rods 64, 66 are not precisely radial and thesecond truss rods 64 at one side of the dividing wall 40 are not alignedwith the second truss rods 66 at the other side of the dividing wall 40.Each of the plurality of radial truss rods at each height level of thehoop segments 21 is fixed at the respective fixture 60, 62 and extendsthrough a stave in the wall 14 of the tank to be secured there by afastener located at the L cross-section hoop segment 21 where the secondtruss rods are tightened. Tightening of the second truss rod 64, 66draws the hoop segments 21 inward against the tank staves on which thehoop fragments rest and pulls the hoop segments radially inward, so thatthe hoops 18 at the top and bottom and the hoop segments 19, 21 bias thestaves of the tank wall inward.

To further secure the staves of the tank wall, at height intervals alongthe height of the tank wall 14 below the first truss rods, there are aplurality, with three being illustrated, horizontal channels 72 at thediameter and channels 74 at chords across the tank. The horizontalchannels are attached at fastenings 76 located at the opposite ends ofthe horizontal channels to respective staves at the side wall 14 of thetank. As seen in FIG. 2, each horizontal channel 72, 74 either passesthrough or at least is connected to the vertical I-beams 48, 50. Thehorizontal channels further support the staves of the tank wall 14.

While the tank 11, 12, 14 and the dividing wall 40 are made of wood, theinternal first and second truss rods 54, 56, 64, 66 which extend acrossand through the tank are preferably of stainless steel, so that theywill not corrode in the presence of water. The internal channels andbeams, which are also exposed to water, are preferably of a coated steelalso to prevent corrosion of those steel elements. The external hoopsand compression rings 18 and 19 are preferably of galvanized steel.Although they are not exposed to the water, nonetheless their corrosionis undesirable as it could weaken the important tightening for clampingparts.

In this embodiment, there is secure mounting of the wooden dividing wallinside the wooden tank with both the tank wall and the dividing wallbeing comprised of staves or narrow elongate boards.

The respective dimensions of the boards or staves is a matter of choicefor the particular size, shape and wooden material of the tank. Thechoice of wood for the tank is also a matter of choice so long as it hasthe required strength and stiffness, imperviousness to water, reducedwarping, long life, and other characteristics one would want from a woodstructure continuously subjected to water.

Although the present invention has been described in relation toparticular embodiments thereof, many other variations and modificationsand other uses will become apparent to those skilled in the art. It ispreferred, therefore, that the present invention be limited not by thespecific disclosure herein, but only by the appended claims.

What is claimed is:
 1. An apparatus for securing together elements which define a tank for holding liquid and for preventing escape of liquid from the tank, wherein the tank that is defined comprises a plurality of elements arranged for defining a periphery of the tank, including adjacent elements which contact each other and are positioned to define the periphery, and the adjacent elements are urged together for preventing leakage from the tank between the adjacent elements; the apparatus comprising: at least three hoops around the periphery of the tank and at an outside of the tank elements, one hoop is toward a top of the tank periphery, one hoop is toward a bottom of the tank periphery and one is between the top and bottom location hoops; the hoops being of respective circumferential lengths for being tightened around the outside of the tank elements and for squeezing adjacent tank elements together for preventing leakage between the adjacent elements; a plurality of truss rods connected at at least one of the hoops at various locations around the hoop, a support in the tank for each of the truss rods wherein the truss rods are connected between the at least one hoop at the periphery of the tank and the support for the truss rod inside the tank; and a device for tightening each of the truss rods between the at least one hoop and the support in the tank for pulling the at least one hoop inward against the periphery of the tank elements and toward the truss rod support in the tank for thereby also squeezing the adjacent tank elements together to cause the tank wall to prevent leakage between the adjacent tank elements.
 2. The securing apparatus of claim 1, wherein the at least one hoop is divided into a plurality of separate partially circumferential hoop segments which are positioned and shaped to together define the at least one hoop; and at least one of the truss rods being connected with each of the plurality of the hoop segments and the truss rods being tightened by the device for tightening each of the truss rods to urge each of the hoop segments of the at least one hoop inward toward the supports to squeeze the adjacent elements of the tank together.
 3. The apparatus of claim 2, wherein the hoop segments of the at least one hoop are circumferentially spaced apart around the at least one hoop.
 4. The apparatus of claim 2, further comprising: a divider extending across the tank and having opposite ends engaging respective divider engaging hoop segments at the tank periphery; second truss rods extending across the tank and having respective second opposite ends that engage the respective divider engaging hoop segments at each end of the second truss rods; and the second truss rods being tightened for pulling the divider engaging hoop segments against the divider and sealing the divider engaging hoop segments to the divider to prevent leakage past the divider.
 5. The apparatus of claim 4, further comprising a bottom of the tank secured to the tank elements in a manner to prevent leakage between the tank elements and the bottom of the tank.
 6. The apparatus of claim 5, further comprising the supports for the end of each truss rod are attached at respective locations in the tank along the length of the divider across the tank.
 7. The apparatus of claim 3, wherein the tank elements comprise vertically extending staves arranged in an array defining adjacent staves around and defining the periphery of the tank and extending the height of the periphery of the tank between the one hoop toward the bottom of the tank periphery and the one hoop toward the top of the tank periphery; the hoops engaging outsides of the staves, and the hoops and the array of staves are respectively sized and the hoops are of such circumference that the hoops are tightened by tightening of the truss rods against the hoops to which the truss rods are attached for applying inwardly directed force on the staves for squeezing the staves together.
 8. The apparatus of claim 7, wherein the divider comprises: a vertical array of divider staves arranged one above the other, each divider stave extending across the tank to the vertically extending staves at the periphery of the tank; at least one beam extending vertically along the divider and pressing against the divider to hold adjacent divider staves together in a sealing manner to prevent leakage between adjacent divider staves.
 9. The apparatus of claim 8, further comprising a respective one of the vertically extending beams at each opposite side of the divider and the beams are placed to cooperate to hold adjacent divider staves of the divider in a leakage preventing manner.
 10. The apparatus of claim 2, wherein fewer than all of the hoops comprise the array of hoop segments, and there are respective ones of the truss rods for each of the hoops comprised of hoop segments.
 11. The apparatus of claim 10, wherein the hoop toward the top of the tank periphery and the hoop toward the bottom of the tank periphery are continuous in circumference and not defined by separate hoop segments.
 12. The apparatus of claim 4, further comprising third truss rods at about the heights of some of the hoops and extending across the tank along chords of the tank shape and extending across the directions of the truss rods, the third truss rods having ends that are secured to the elements of the tank at the periphery of the tank.
 13. The apparatus of claim 12, wherein the third truss rods extend across the divider. 